Overall there was a 20% drop in the incidence of dementia in the
population aged 65 or over, but people living in deprived areas remained
at a higher risk than others.

The Medical Research Council Cognitive Function and Ageing Study
(CFAS) saw researchers at the University of Cambridge, Newcastle
University, Nottingham University and the University of East Anglia
interviewing 7,500 people in three regions of the UK, and repeated
interviews after two years to estimate incidence.

This was then repeated 20 years later in a new group of 7,500 people from the same localities aged 65 and over.

The scientists found that as the population of over-65s was growing,
the increase in the number of dementia cases recorded per year was far
smaller than expected - from 183,000 recorded in 1991 to 210,000 cases
per year at the present time.

Of the almost 210,000 per year currently diagnosed, 74,000 are men and 35,000 women, the paper published in Nature Communications said.

But the study also concluded more could be done to prevent the
disease, estimating some 30% of cases may have been avoidable through
lifestyle changes.

The paper concluded that brain health is changing across generations
but, with people in disadvantaged circumstances most at risk, positive
change was most likely with major investment in population health
measures.

The paper said: ‘Lack in progress in access to education, patterns of
malnutrition in childhood and persistent in equalities within and
across countries will play out. Policy makers and politicians will need
to take into account the now compelling evidence that such changes in
the onset and occurrence of dementia are possible.’